This invention relates to a carrier for printed circuit boards, and more particularly to a lightweight, durable carrier which can be adjusted to accommodate circuit boards of differing depths and widths, and which facilitates stacking and transporting of the circuit boards.
Printed circuit boards are used extensively in all types of electrical equipment. Such circuit boards are formed as substantially uniformly shaped cards which are stacked together in the equipment. During the course of fabrication or of actual use, it is often necessary to handle a large number of the boards simultaneously. For this purpose it is best to provide for a carrier which can stack the printed circuit boards uniformly with respect to each other at sufficiently spaced apart locations to avoid interference from one board to the next one.
The circuit boards occasionally have to be stored or transported in a vertical orientation, while in other situations a horizontal orientation is more appropriate. Furthermore, the types of support available for the carrier will substantially differ depending upon the particular type of transportion or use required for the printed circuit boards.
By way of example, during production of the circuit boards themselves, they generally may be handled either vertically or horizontally. However, if they are wet from processing, vertical orientation is generally preferred to permit drainage. At this stage of the production, the circuit boards can be placed closer together but still cannot touch each other. Because of the closer arrangement, denser storage is facilitated which results in more efficient use of the space.
From the time when the components are placed on the circuit board until they are suitably soldered, the boards must be generally kept in a horizontal plane to prevent dislocation of the components. After the components are soldered, the boards again may be transported either horizontally or vertically.
In any event, the boards may be securely held during all the various fabrication procedures while preventing them from shifting or sliding out from the carrier.
During the course of their production, or prior to actual use, the printed circuit boards require transportation from one facility to the next. Such transportation may occur by various means. For example, when they are transported for long distances, they may be placed in a van from one manufacturing location to another. Where security is important, they may be placed in an enclosed cabinet. Occasionally, for storing them at a particular facility, they may be placed on various types of stationary shelving. Such shelving may be solid, formed of a series of rails, or may contain undershelf slides from which the carrier will depend. Of course, in transporting the carriers, it is necessary to grasp them either manually or automatically to move them about. The carrier must also be suitable manufactured for placement on a support surface.
An additional requirement for suitable carriers is that they permit adjustability for different types and sizes of printed circuit boards. Although in a particular situation printed circuit boards of a common size will be stacked together, nevertheless from one application to the next, the size of the circuit boards may vary and accordingly the carrier must be adjustable to accommodate such variability in size of the printed circuit boards. The size itself may vary in either the width or depth dimensions of the circuit boards. Furthermore, although a carrier may be of the size limited to retain a specific number of stacked boards, where many boards must be transported or undergo a common manufacturing operation, it is desirable to facilitate stacking of one carrier on the next in a secure stacking relationship.
At present there are numerous types of carrier available for printed circuit boards. Some of these are in the form of baskets, others form cabinets, or similar solid type containers. Many of these are inflexible and cannot be adjusted to accommodate the different sized printed circuit boards. Still other types of carriers have complex designs which add weight to the carrier and often present problems in manipulating the carriers. This is especially a problem when hand carrying of the carrier is required. It is also a problem where various types of manufacturing operations are needed on the printed circuit boards, such as baking, and extra precautions must be taken to accommodate the excessive weight of the carrier or handling basket which holds the boards during this process.
Of course, one of the most difficult problems with prior art devices is that they often do not provide for suitable adjustability. While they may provide some capability for adjustment, in one varying dimension of the printed circuit board, there is insufficient versatility to utilize these carriers. It is necessary for a carrier to be adjustable and accommodate circuit boards where both the width and depth dimension can vary. Furthermore, stackability of the carriers is an important requirement, often not achievable with prior art designs.
One of the most important problems of prior art designs concerns the ability to transport the carriers. While handles may be provided on some devices, such handles are often insufficient for the varied types of transporting means available. While such handles may be usable for vans, they may be unsuited for shelves or other storage facility.